7. Design Guidelines
7.1 Layout and Placement
For optimal performance of the BGM220S the following guidelines are recommended:
• Place the module 1.50 mm from the edge of the copper “keep-in” area at the middle of the long edge of the application PCB, as
Figure 7.1 Recommended Layout for BGM220S on page 32
.
• Copy the exact antenna design from
Figure 7.2 Antenna Layout With Coordinates on page 33
with the values for coordinates A to
L given in
Table 7.1 Antenna Polygon Coordinates, Referenced to Center of BGM220S on page 33
.
• Make a cutout in all lower layers aligned with the right edge and the bottom edge of the antenna as indicated by the yellow box in
Figure 7.3 Antenna Clearance in Inner and Bottom Layers on page 34
• Connect all ground pads directly to a solid ground plane in the top layer.
• Connect RF_2G4 to ANT_IN through a 0-ohm resistor.
• The 0-ohm gives the ability to test conducted and to evaluate the antenna impedance in the design.
• Place ground vias as close to the ground pads of the BGM220S as possible.
• Place ground vias along the antenna loop right and bottom side.
• Place ground vias along the edges of the application board.
• Do not place plastic or any other dielectric material in contact with the antenna.
• A minimum clearance of 0.5 mm is advised.
• Solder mask, conformal coating and other thin dielectric layers are acceptable directly on top of the antenna region.
Figure 7.1. Recommended Layout for BGM220S
BGM220S Wireless Gecko Bluetooth
®
Module Data Sheet
Design Guidelines
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